Cypress Hills Interprovincial Park - Alberta has three
significant lakes
within its borders:

Elkwater Lake (202 hectares);

Reesor Lake (51 hectares); and

Spruce Coulee Reservoir (20 hectares).

All three lakes provide recreational opportunities such as
fishing and boating. The lakes also supply water for agricultural
purposes.

Summer Lake Water Sampling

It is important that the parks lakes be monitored on a regular
basis to ensure water quality is maintained. In May, June, July,
August, and September samples are taken from the lakes once a
month. These samples determine the level of fertility for each
lake. Most people believe that a lake that is murky or green with
algae is of poor quality; however, in fact, algae is an indicator
of high nutrient levles. The level of fertility is assessed by
measuring three indicators:

transparency;

chlorophyll (algae biomass); and

total phosphorus.

Water samples are obtained at random locations, processed,
packaged and sent to the Environmental Monitoring Branch of Alberta
Environment & sustainable Resource Development for testing.

Winter Lake Water Sampling

As winter progresses and ice cover increases, the level
of dissolved oxygen levels in the lakes gradually decreases.
In the winter, water samples are gathered to determine the level of
dissolved oxygen at various water depths.

Determining dissolved oxygen levels is important because fish
die if levels are too low. Winterkill is caused by decomposing
aquatic vegetation using up a lake's oxygen.

Each month, tests are conducted on each lake to determine
dissolved oxygen. levels. That information is forwarded to
fisheries biologists with Natural Resources Canada.